An exception of type Microsoft.SharePoint.Administration.SPUpdatedConcurrencyException was thrown. Additional exception information: An update conflict has occurred, and you must re-try this action. The object SPUpgradeSession Name=Upgrade-20120310-130057-953 was updated by XXXX\svcSP_Farm, in the PSCONFIG (5168) process, on machine APP01. View the tracing log for more information about the conflict.